On logics and semantics for general logic programs

We suggest a general logical formalism for Logic Programming (called a biconsequence relation) based on a four-valued inference. We show that it forms a proper setting for representing logic programs of a most general kind and for describing fogies and semantics that characterize their behavior. In this way we also extend the connection between Logic and Logic Programming beyond positive programs. A uniform representation of various semantics for logic programs is presented. The main conclusion from this representation is that the distinction between these semantics can be largely attributed to the difference in their underlying (monotonic) logical systems. Moreover, in most cases the difference can even be reduced to that of the language, that is, to the difference in the logical connectives allowed for representing derivable information. In addition, it allows us to see a reasoning about logic programs as a most simple kind of nonmonotonic reasoning in general.